1. Field of the Invention
The present invention relates to head parts for front fork and more particularly, to an angle-adjusting head parts for front fork that allows adjustment to change the wheel span subject to the condition of the road and the rider's requirements.
2. Description of the Related Art
The head tube of a bicycle is connected with the front fork stem and the handlebar stem by means of a set of head parts. Because the angle of the front fork stem is determined subject to the angle of the head tube, the front fork stem can simply be rotated relative to the head tube subject to the arrangement of the upper and lower bearings in the head parts. To an ordinary bicycle rider, it is not necessary to adjust the angle of the front fork stem. However, to a bicycle racer who may need to race on different racing roads of different road conditions, riding controllability and stability are critical.
However, the riding controllability and stability and the steering ability are determined subject to the wheel span and the angle of the front fork stem. Shortening the wheel span relatively increases the sensitivity of riding controllability to fit for a road segment having multiple turns. Extending the wheel span increases the sensitivity of riding stability to fit for high-speed long straight riding. The wheel spans of regular bicycle frames are properly designed to keep the sensitivity and the stability in balance. However, regular bicycles do not allow adjustment of the angle of the front fork stem and the wheel span to fit different requirements of different riders.